1. Technical Field
Exemplary embodiments of present invention relate to semiconductor fabrication technology, and more particularly, to a method of manufacturing a phase-change memory device having a hole and a method of manufacturing a semiconductor device.
2. Related Art
Next-generation semiconductor memory devices are to be provided with properties such as lower power consumption in addition to non-volatility of a general flash memory device, high speed operation of a static random access memory (SRAM), and high integration of dynamic RAM (DRAM). Research has been conducted on the next-generation semiconductor memory devices such as ferroelectric RAMs (FRAMs), magnetic RAMs (MRAMs), phase-change RAMs (PCRAMs), and nano floating gate memories (NFGMs) with lower power consumption and better characteristics of retention and read/write of data as compared with the general memory device. Among the next-generation semiconductor memory devices, since the PCRAM (hereinafter, referred to as phase-change memory device) has a simple structure and may be fabricated at a lower cost to operate at high speed, the phase-change memory device has been actively researched/developed as the next-generation semiconductor memory devices.
One of important issues in the phase-change memory device is to reduce a reset current for phase-change. To reduce the reset current, an area of a heating electrode may be smaller.
However, as the integration density of the semiconductor memory devices is increased, photolithography technology reaches the limit in forming a pattern and a hole. Thus, it is difficult to form an ultrafine lower electrode contact for obtaining the reset current at a desired amount.
A spacer may be formed on a sidewall of a contact hole to form a fine contact hole, but an upper sidewall of a contact hole may be removed in such a forming process including an anisotropic etching process. As a result, an area of an upper portion of a contact hole is extended.